Option B, connections between neurons become stronger and faster, is the right answer.
A Neuron is an electrically sensitive cell that used to interact with other organisms via functional joints called synapses. Teenage is the time of notable maturity and development in the brain of the teenagers. During the teenage, stem cells present in the brain of adults may restore working neurons during the life of an organism. Therefore, it may be said that connections between neurons become stronger and faster during the teenage.